Petoskey Stone
Hexagonaria percarinata
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Petoskey Stone
Hexagonaria percarinata
Coquina / Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
Pink Granite
Phaneritic Felsic Igneous Plutonic Rock
Chert / Red Jasper
Microcrystalline Quartz (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Amber
Succinite (fossilized resin)
Aquamarine
Beryl (Be3Al2Si6O18)
Orthoceras Fossil in Limestone
Orthoceras regulare (Class Cephalopoda; Order Orthocerida)
Septarian Nodule (Septarian Stone)
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
Concrete / Conglomerate (Man-made)
Artificial Conglomerate (Cementitious Composite)
Tanzanite (Rough)
Blue Zoisite (Ca2Al3(SiO4)3(OH))
Granite
Granite (Phaneritic Acidic Igneous Rock)
Amazonite
K(AlSi3O8) - Potassium Aluminum Silicate
Fairburn Agate
Cryptocrystalline Quartz (SiO2)
Onyx (Black Onyx)
Onyx (Silicon Dioxide, SiO2)
Gold Flake (Placer Gold)
Native Gold (Au)
Sandstone
Arenite (SiO2 principal)
Ocean Jasper (Orbicular Jasper)
Spherulitic Chalcedony (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Amethyst Geode
Silicon Dioxide with impurities (SiO2)
Blue Quartzite
Quartzite with inclusions (often Dumortierite or Magnesio-riebeckite), SiO2
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Sandstone
Arenite (composed primarily of SiO2)
Yellow Jasper
Silicon Dioxide (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Picture Jasper
Silicon dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Aura Quartz (Titanium Quartz)
Titanium-coated Silicon Dioxide (SiO2 + Ti)
Fossiliferous Limestone (with Coralline Inclusions)
Calcium Carbonate (CaCO3)
Pink Granite (Water-worn Cobble)
Granite (Alkali-feldspar granite)
Malachite
Copper carbonate hydroxide [Cu2CO3(OH)2]
Ruby, Emerald, and Sapphire (Corundum and Beryl)
Corundum (Al2O3) and Beryl (Be3Al2Si6O18)
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Flower Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
Amethyst (Chevron Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Green Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Granodiorite
Phaneritic Plutonic Granodiorite
Black Onyx
Silicon dioxide (SiO2) with parallel banded structure
Sandstone (Quartzose)
Arenite (primarily SiO2)
Lake Superior Agate
Banded Chalcedony (Silicon Dioxide / SiO2)
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)